d62bcc8b07
pg_receivewal includes since cada1af the option --compress, to allow the compression of WAL segments using gzip, with a value of 0 (the default) meaning that no compression can be used. This commit introduces a new option, called --compression-method, able to use as values "none", the default, and "gzip", to make things more extensible. The case of --compress=0 becomes fuzzy with this option layer, so we have made the choice to make pg_receivewal return an error when using "none" and a non-zero compression level, meaning that the authorized values of --compress are now [1,9] instead of [0,9]. Not specifying --compress with "gzip" as compression method makes pg_receivewal use the default of zlib instead (Z_DEFAULT_COMPRESSION). The code in charge of finding the streaming start LSN when scanning the existing archives is refactored and made more extensible. While on it, rename "compression" to "compression_level" in walmethods.c, to reduce the confusion with the introduction of the compression method, even if the tar method used by pg_basebackup does not rely on the compression method (yet, at least), but just on the compression level (this area could be improved more, actually). This is in preparation for an upcoming patch that adds LZ4 support to pg_receivewal. Author: Georgios Kokolatos Reviewed-by: Michael Paquier, Jian Guo, Magnus Hagander, Dilip Kumar, Robert Haas Discussion: https://postgr.es/m/ZCm1J5vfyQ2E6dYvXz8si39HQ2gwxSZ3IpYaVgYa3lUwY88SLapx9EEnOf5uEwrddhx2twG7zYKjVeuP5MwZXCNPybtsGouDsAD1o2L_I5E=@pm.me
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.